Divertor and first wall armor design for the TIBER-II engineering test reactor

Abstract

TIBER-II is a compact, high-power-density, steady-state current-drive engineering test reactor that uses a double-null divertor configuration, operating in the high recycle mode with low particle temperature. The nominal peak heat flux is 3.3 MW/m 2 , with off-normal condition peaks of up to 6.6 MW/m 2 . Plasma disruptions may cause peak energy deposition of up to 13 MJ/m 2 . The design uses water-cooled copper alloy tubes with brazed-on protective tiles. During early operating phases when disruptions may be frequent, these tiles will be made of carbon. During the nuclear testing phase, disruptions must be limited so that more erosion-resistant tungsten tiles may be used. The first walls of TIBER-II experience a heat flux of 0.23 MW/m 2 with disruption energy density of 2.4 MJ/m 2 . They are protected by carbon-carbon composite armor tiles. The TIBER-II design requirements are challenging, and although the divertor and first wall armor designs successfully meet these requirements, significant issues must be resolved to verify their performance. These critical issues and the R&D required to resolve them are described.